Please help! I'm having a Meltdown!

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Kenflo

Kenflo

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Ok I have an alternator related question. The car has a new EZ wire harness installed, alternator and battery are all new as well. The car has been out on a few cruises and all seemed to be working fine until I noticed a drop in voltage and she stalled. I noticed on the alternator that on one of the field wire connections that the rubber/plastic washer had melted due to the heat of the headers (I think) and the loose wire was causing the car to stall out. I hooked up the field connector without the rubber insulator washer and now when I turn the key the wires connecting to the ignition are starting to smoke as well as the alternator field wires are hot to touch as well. So my question is about the rubber insulator washer on the alternator. Was it a mistake to try to hook up the wiring on the alternator without it and is this causing the melted wiring?
 
Yes, likely a mistake. I have to assume that your system is 1971 or later? One field connection is powered by key in "RUN" (blue), the other connection (green) is pulled lot ground in a pulsing way, as necessary to energize the field for regulation. The colors use are from OEM harness, have no idea about EZ colors. The blue also powers ignition, so a fault (no insulator there, and screwing down makes connection to ground), will kill ignition power, melt wire insulation and possibly start a fire, or burn fusible link.

There are better insulators than rubber, things like nylon, phenolic, ceramic.... Sounds like header is too close, or too hot. That brings to question about mount location, or if engine timing is too retarded, resulting in burning fuel too late. That can burn up headers quickly, many do that by not using vacuum advance distributor, and expect engine to properly highway cruise.
 
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I've never read of header pipes melting alternator connections so I'll guess the root of the problem is in the alternator.
 
yes - it was/is a mistake to try to run it w/o that insulator.. but it wasn't the heat from the header that melted it in the first place (at least I have never heard of such a thing). You've probably either got something hooked up wrong, a bad ground somewhere or something is failing..
 
So if that field terminal connection is a brush holder, What happens when the brush wears away to the point it leaves the holder ? Short circuit with isolator and/or holder melt down possible?
 
The brush is often bonded to terminal with braided copper tether. It is inside the spring and is sintered in brush. The dimension between brush holder and slip ring or slip plate, is tight enough to keep short brush in. Typically brushes skip contact due to lack of travel, thus protect slip surfaces.
 
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What I did notice on the alternator field connections when the car stalled was that both connections were loose and the one insulator was brittle and when I tightened it just cracked and fell apart. I am going to try with new insulator washers and see what happens.
 
It's never good letting the smoke out. The EPA must be notified. Several gob't agencies. It's terrible. Plus it smells bad. Girls generally don't like this
 
Kenflo said:
What I did notice on the alternator field connections when the car stalled was that both connections were loose and the one insulator was brittle and when I tightened it just cracked and fell apart. I am going to try with new insulator washers and see what happens.
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After changing the insulators and before connecting wires to terminals, an Ohm meter could be used to verify the terminals are isolated from ground. Meters do this better, than visual inspection.
 
I made the mistake (go ahead and kick me) of putting a NAPA Chinese re-manufactured alternator on my '70 Dart in February. It was defective and both field terminals were grounded. Perhaps it was a newer case re-manufactured to be used on a pre-1970, I don't know. At any rate I melted my blue field wire all the way up to the ignition switch. As mentioned above check that those field wires terminals are not grounded if being used on a two wire 1970 and on car. If I ever have to replace an alternator again, it's the first thing I'll do after I open the box.
 
Robj said:
I made the mistake (go ahead and kick me) of putting a NAPA Chinese re-manufactured alternator on my '70 Dart in February. It was defective and both field terminals were grounded.
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WAAAAAAYYYYYYY too much of this. Many rebuilds seem to come with at least one field grounded, so if the customer is unaware, they have a 50-50 chance of getting the switched 12V hooked to the grounded terminal
 
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